The present invention is directed to generation of an optical waveform and more specifically to a method and a system for generating optical waveforms from electrical signals.
Within modem switching and storage systems, digitizing and the manipulation of data is performed almost exclusively in the electrical mode as opposed to the optical mode. The primary reason is that the electrical mode offers a plethora of switching components and techniques developed over almost a century of use. While optics have been used, they have predominantly been deployed in an analog mode. Digital optics were pioneered by the telecommunications industry and also used somewhat in the data storage industry. However, digital optics have not, until recently, been viewed by the universal signaling and control industry as a practical (i.e. economical) solution.
With the advent of high speed data transmission requirements in such areas as networks, buses, and the internet, digitally pulsed optical signal techniques, switchers and media have experienced an increasingly strong demand.
A key component in satisfying this surging demand is the provision of a signal modulated light source to generate the encoded signal pattern. One of the more prominent devices being utilized for this function is the LED (Light Emitting Diode). An LED is a solid state device, which emits photons of light, based on the direct electronic switching of its input junction. The light pulses generated are relatively fast (i. e. solid state rates). The disadvantage of LEDs, however, is that the light power outputted from the device is relatively low. The LED is typically rated in millivolts.
An alternative device to the LED is an optical switch, such as a Mach-Zehnder, for example. This device is controlled by an electrical input, which gates a separately provided light input (as opposed to generating light from within the device) through the device to its output when the device is xe2x80x9con.xe2x80x9d No light is outputted when the device is xe2x80x9coffxe2x80x9d. A third alternative, is a Lucent device titled xe2x80x9cSeedsxe2x80x9d (Self Electro-Optic Effect Device). This device attenuates (at a specific frequency range) or passes a light input through the device to the output. It is also controlled by an electronic signal input. All of these aforementioned devices have relatively low light power outputs. There are other optical digital pulse producing devices, such as a xe2x80x9cChirped-Pulsed Laserxe2x80x9d, which are in experimental stages and commercially available.
Inert gas lasers (i. e. neon, argon), have also been utilized as a source of optical digital pulse patterns. Their applications tend to demand high lumen power and permit the output waveform to have extended pulse widths. These waveforms are typically generated by modulating the gas laser""s output. The modulation techniques have included mechanical shutters in the early applications and optical attenuators more recently, both of which allow or deny the passage of the output light beam. These techniques produce significantly higher power photonic digital outputs but at a much slower digital rate than the solid state or electroa-optic techniques mentioned above. Another category of high powered laser, is the xe2x80x9cUltra-fast Laserxe2x80x9d which can deliver extremely high powered beams concentrated within a tight pulse. This category will not be addressed herein; however, as the delivery systems are extremely expensive (in excess of a million dollars) and the pulse repeatability patterns are not conducive to the needs addressed by the present invention.
These two extremes, high power or low power, have been successfully utilized in various industries demanding their unique but opposing characteristics. At present, there is no middle ground device which would offer significant photonic output power at high speeds (i. e. narrow pulse widths), and at a competitive xe2x80x9ccommercial electronics unitxe2x80x9d cost.
It is therefore, an object of the present invention, to overcome the shortcomings highlighted above by providing a method and a system for converting electrical signals to multi-channel optical digital waveform, the individual waves being superpositioned to form a stacked optical pulse.
According to an exemplary embodiment of the present invention, a method for converting an electrical signal to an optical pulse is disclosed, the method comprising the steps of: receiving said electrical signal; sampling said received signal to obtain a single channel data; converting said single channel data to multi-channel data; converting said multi-channel data to a plurality of electrical pulses wherein said first plurality corresponds in number to a number of channels in the multi-channel data; inputting said first plurality of electrical pulses and a light source output into a switch array comprising a plurality of optical switches to obtain a multi-channel optical waveform comprising a plurality of optical waveforms; and superpositioning (or, superimposing) each of the third plurality of optical waveforms to generate a stacked optical pulse.
According to another exemplary embodiment of the present invention, a system for onverting an electrical signal to an optical waveform is disclosed, the system comprising: a digital converter means for receiving and sampling said electrical signal to obtain a single channel binary data; a channel conversion means for converting said single channel data to multi-channel data; a digital pulse generation means for converting said multi-channel data to a plurality of electrical pulses; a switch means, comprising a plurality of optical switches, for receiving said plurality of electrical pulses and a light source output, with each of said electrical pulses corresponding to at least one of the optical switches, and for outputting a multi-channel optical waveform comprising a plurality of optical waveforms; and a stacking means for superpositioning the plurality of optical waveforms from the multi-channel optical waveform.
According to yet another exemplary embodiment of the present invention, a method of using optical pulses to write data generated from an electrical signal is disclosed, the method comprising the steps of: receiving an electrical signal; sampling said received signal to obtain a single channel binary data; converting said single channel data to multi-channel binary data; converting said multi-channel data to a plurality of electrical pulses; inputting said plurality of electrical pulses and a light source output into a switch array comprising a plurality of optical switches, with each of said electrical pulses corresponding to at least one of the plurality of optical switches, to obtain a multi-channel optical pulse waveform comprising a plurality of optical waveforms; stacking the optical waveform by superpositioning an amplitude of each of the plurality of optical waveforms to form a stacked optical pulse; deriving data from said stacked optical waveform; and writing said derived data onto a storage medium on a non real-time basis.
According to a further exemplary embodiment of the present invention, a method for converting an electrical signal to an optical pulse is disclosed, the method comprising the steps of: receiving said electrical signal; sampling said received signal to obtain a single channel data; converting said single channel data to multi-channel data; converting said multi-channel data to a plurality of optical pulses; inputting said plurality of optical pulses and a light source output into a switch array comprising a plurality of optical switches, with each of said plurality of optical pulses corresponding to at least one of the optical switches, to obtain a multi-channel optical waveform comprising a plurality of optical waveforms; and superpositioning each of the plurality of optical waveforms to generate a stacked optical pulse.